My take on any kind of Dhar usage is that is is not worth it. Let us assume that there is a 'safe' way to do it with our knowledge and equipment. Let's even assume that it extends to all winds, not just Ulgu. A way to use it to just nuke the bad guys and nothing else. It would still be limited to us. It would be a work of generations to get something like that approved, if it ever could be. In that time we, and any potential successors of ours would either have to not use it, or do it in utmost secrecy, or risk undoing whatever progress was achieved and getting hunted down by all our allies. But let's say that it can be done. In a century the Empire officially approves of Magisters using whatever safe method of manipulating Dhar if they have the proper equipment. Which, as far as we know requires a Runelord on the level of Kragg to make. Still, it might be possible to do a lesser variant(just the Rune of Valaya's Vengeance) with lesser runesmiths. The Dwarfs are still not going to mass produce these. Each is going to have to be earned. All of this for, in my opinion, a marginal benefit. Having a safe way to use Dhar will provide some use for less nuke-capable winds, occasional power spike in dire situations and perhaps more potential for Dhar cleanup, but it is not free lunch. It would require a lot of time to train this new way of spellcasting, and it would almost certainly increase the attrition rate of young wizards as Dhar is a lot more volatile than normal winds. Then there is also the problem with having Dhar usage, in any way, considered acceptable. You would have a lot more random idiots trying it and failing/getting corrupted. And anyone actually trained would be a lot more dangerous if they go Black Magister(of their own free will, as it is known to happen occasionally) as they would already heve some knowledge of how to use Dhar.
On the other side we can spend that time developing new improvements to spellcasting, enchanting, rituals, or whatever else that is not forbidden on the pain of death. Any of these improvements can be shared with our College, incrementally improving the collective ability. So while we are in a unique situation where we might be able to develop a safe way to use Dhar, it is not actually worth it compared to other options available.